现代通信原理课件chapterone(编辑修改稿)

现代通信原理课件chapterone(编辑修改稿)内容摘要：

munication Digital and Analog source and system 19 Digital and Analog source and system (classification of munication system) according to physical properties of information : Telephone /data /image and so on according to frequency : baseband transmitting/ bandpass transmitting system according to transmitting medium : wire /wireless according to multiplexing patterm: Frequency division multiplexing access(FDMA) Time division multiplexing access(TDMS) Code division multiplexing access(CDMA) 20 Digital and Analog source and system • Classification of munication patterm • Peer to peer munication : simplex。 half duplex。 duplex • Parallel transmitting munication • Series transmitting munication 21 1. Key conception Digital information source produces a finite set of possible messages. Such as typewriter and keyboard Analog information source produces messages that are defined on continuum. Digital munication system transfers information from a digital source to the intended receiver(sink) Analog munication system transfers information from a analog source to the intended receiver(sink) Digital and Analog source and system 22 1) Deterministic waveform It can be modeled as a pletely specified function of time 2) Random waveform(stochastic waveform) It can not be pletely specified as a function of time and must be modeled probabilistically 1) Example: Deterministic and Random waveforms )c o s ()( 00   tAt23 1)Property of the book a. from easiness to difficulty b. from concept to performance analysis 2) Methods of learning it a. reading it again and again b. grasping the important concept c. understanding the basic munication system by deriving some key formula d. simulation using Matlab The propert。